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What is Engine Braking and Why is it Important?

Learning how to operate your vehicle’s brake system is one of the first things covered when learning how to drive. Using the footbrake is the most common way to reduce your speed, both in an emergency and in normal conditions.

But, is using the footbrake the most efficient way to slow down? We’re exploring the concept of engine braking and what it can do for your vehicle’s longevity.

What is Engine Braking?

In simple terms, engine braking is the process of slowing down your car by freeing your foot from the accelerator and shifting down through the gears.

In more technical terms, engine braking in standard gasoline cars works by limiting airflow to the engine, causing decelerative forces in the engine to decrease the speed in which the wheels are rotating.

When you take your foot off the accelerator pedal, the throttle valve closes suddenly. The engine will continue to try to suck in air, but since the throttle valve is closed, only a little amount of air will reach the engine. This causes a high manifold vacuum that the cylinders have to work against.

Due to the vacuum, the energy in the engine lowers which causes the engine to drop in power from inefficient combustion.

Why is Engine Braking Important?

It is safer.

Engine braking gives you more control over the speed of your car. If done correctly, it means that the driver is paying close attention to the road, therefore driving safely.

For example, if you see traffic begin to build and slow down in front of you, choose to engine brake rather than wait until the last moment possible to slam on your brakes. This gives you and those around you more time to react to the changing speed.

Engine braking also puts you in a better position to react to the unexpected. By being in a lower gear, you can either speed up or slow down to avoid a sudden hazard. It also keeps you from sharp braking which can lead to less rear ends on the road.

It reduces wear and tear on your brakes.

Since caliper brakes and drum brakes both rely on friction, they wear down whenever the brake pedal is used. Since the car is slowing down passively, it allows you to control the deceleration so that you only need to apply the brakes at a much slower pace for a shorter amount of time.

Especially on long descents on mountains, hills, or just extended periods of driving, choosing to engine brake is a smart decision. Your brakes don’t get overheated on the descent, which allows them to operate normally and not become damaged from getting too warm.

Engine braking means less heat, wear, and fade on the brakes. As a result, the lifetime of your brakes is longer, and they increase value.

It increases fuel economy.

Engine braking over normal braking is far more fuel efficient. Since it turns off fuel consumption, as opposed to simply braking or putting the car in neutral, you are using less fuel.

You will use less gas when pulling away in a lower gear than you will if you’re pulling away at low speeds in a higher gear. Although you might think engine braking would save only a little fuel here and there, the amount you could save on long trips can add up, giving you more bang for your buck.

It is better for the engine.

There is a common myth that engine braking is harmful to your car and bad practice. Engine braking does not harm your car; in fact, it is good for it!

Engines run at thousands of revs per minute for sometimes hours and hours at a time when you take road trips. Changing down doesn’t cause any damage, because engines were designed to be driven this way. While many car advancements have been made, engines have essentially stayed the same for the past few decades. By gradually slowing down and shifting your gears from 5th to 2nd rather than suddenly, your engine will respond better.